In typical safety belt systems, the belt is protracted by the wearer beyond the position required when set, the end or buckle is clamped, and the belt is allowed to retract and assert pressure against the wearer's body. The belt is also locked in the latter position against further protraction to secure the wearer in the seat in the event of a crash or sudden change in the movement of the vehicle. In these conventional systems, the pressure of the belt on the wearer and the resultant excessive confinement, produce uncomfortable effects not needed for safety.
A safety belt retractor which overcomes the latter problem and provides a belt position control mechanism which allows the wearer to ease the pressure of the belt on his body, is disclosed in U.S. Pat. No. 4,002,311. As disclosed in that patent, the wearer effects a slight protraction of the safety belt after it is initially buckled in position on his body. When the belt is then released, it assumes a position which is automatically locked against retraction and which relieves the pressure and tension of the belt on the wearer. The belt remains in that locked position until released by a conscious act of the wearer. Due to the pressure relieving effect of such retractor mechanisms, they are commonly called "comfort locks" or "tension relievers."
The results achieved by the device of U.S. Pat. No. 4,002,311 are accomplished by combining a control mechanism with one of the ratchet wheels of a conventional spring-activated reel-type retractor for a safety belt. The reel-type retractor preferably is of the type controlled by an electrical or inertia responsive device, both of which are well known in the art. In accordance with that patent, a plastic disc is attached to a ratchet wheel and has a plurality of grooves or tracks on its external face adapted to receive a spring follower and stop. The stop-follower rides or slides in and cooperates with the various contours of the tracks or races to effect control of the retractor reel. The precise operation of the control mechanism is described in detail in U.S. Pat. No. 4,002,311, the disclosure of which is hereby incorporated herein by reference.
The present invention is an improvement over the highly advantageous mechanism set forth in U.S. Pat. No. 4,002,311. In particular, the present invention relates to a new stop-follower device which has a unique and beneficial structure as well as a unique and beneficial mounting and biasing mechanism. The stop-follower comprises a bent wire rod which is secured to a plastic housing. The housing in turn is mounted on a pivot pin attached to the retractor, and the housing and pivot pin are spring biased together with a helical coil spring. The spring is attached to the pivot pin through a slot and groove configuration and is also adjustably secured to the housing. The bias of the stop-follower can be adjusted to allow the control mechanism to function in the best manner possible.